The present invention relates to an improved apparatus and method for separating and folding sections of a continuous web, in particular, to folding forms of two or more pages produced from a continuous web. The present invention further relates, in particular, not only to folding forms which have been cut from a continuous web along a perforated or weakened line of folding, but also to those which have been cut slightly offset from a Perforated or weakened line of folding, and thereby have a tail which can be used to identify and separate the folded form from a stack.
The development of high speed printers has been accompanied by the development of improved devices to separate and fold sections of continuous webs containing forms, printouts and reports. Multi-page web sections, forms, printouts, reports and the like are, as a group, referred to herein as forms, and a page is defined as extending between adjacent perforated or weakened lines of folding in a form or continuous web. Known devices which separate continuous webs prior to folding include the Model 7500 Forms Folder with Job Sort available from the Standard Register Co., Dayton, Ohio. These cutter/folder devices transversely cut rapidly moving continuous webs from high speed printers into forms of two or more pages by means of a rotary cutter, and may produce such forms with a tail or tab extending from a perforated line.
Problems have arisen in folding short forms, defined herein as a form of from two to nine pages, particularly two page forms, produced on devices such as the Model 7500 Forms Folder. By virtue of their design, the outfeed gripper rollers typical of such devices positively feed forms into a swing chute for folding, but relinquish positive control of short forms as the trailing end enters the swing chute, before folding is sufficiently underway. As a result, the process of folding short forms has relied on the swing action of the swing chute in combination with frictional engagement between the leading page of the form with the delivery table or with an existing stack of forms thereon. Spirals, knockdown fingers and fluted rollers, which contact forms exiting the swing chute, help initiate folding and provide some control of short forms; however, the short length of short forms also limits the effectiveness of these devices.
One such folding arrangement is shown by Felix, U.S. Pat. No. 4,730,762. Incompletely or poorly folded short forms still result, interfering with the folding and stacking of subsequently issuing forms, and jamming the folding apparatus. These problems have been experienced with three to nine page forms, as well, but with less frequency as the forms become longer. It has been found that as forms become longer, control of the forms is maintained with outfeed gripper rollers, as the rollers are able to positively feed the form through the swing chute and onto the delivery table during folding. This causes the swing chute, spirals and knockdown fingers to more effectively initiate and complete folding of the form. With longer forms, the weight of the stack forming on the delivery table tends to promote correction by flattening misaligned and misfolded forms near the bottom of the stack, and by anchoring the leading edge of incoming forms.
Thus, while improved separating devices can cut forms as short as two pages, folding and stacking of short forms has remained problematic. To avoid such problems, where runs of short forms are desired, additional blank pages have been added to accommodate existing folding apparatuses. This undesirably wastes significant amounts of paper which also must be manually detached from the desired portion of the form.
Other known methods and apparatuses for folding are typically designed to first fold continuous webs into multi-page stacks. Then, the stack of folded forms is severed from the web upon reaching a given number of pages or a predetermined height, as shown, for example, by Kwasnitza U.S. Pat. No. 4,702,135 and Meschi U.S. Pat. No. 4,618,340. Such devices are not designed to accommodate successive short forms arriving from high speed printers and, moreover, include components which are most effective in folding longer forms or continuous webs.
Among the applications that are the most difficult for cutting and folding forms is the intermittent operation of high speed printers at continuously changing speeds, typically from substantially 0.0 feet per minute to 300 feet per minute, but which may reach 500 feet per minute. Such operation requires similar responsive action by form handling devices operating therewith, such as the cutter/folder devices described, and exacerbates folding and stacking problems encountered with short forms.
Accordingly, further improvements are needed to satisfy the demand for more efficient folding apparatuses for high speed devices to fold consecutive short forms cut from a continuous web. If proper folding of short forms is repeatably performed, problems with stacking and jamming of the folder encountered with existing devices may be avoided, and the need to add and then manually separate blank pages from short forms to accomplish folding may be eliminated.